Ever felt the inclination to go all Armageddon on the whole planet? Well now you can let those feelings loose through a new asteroid impact simulator from Purdue University and Imperial College London.

Sure, the Impact: Earth! simulator is fun to play with, but researcher John Spray told Time that it’s an important research tool as well:

“The calculator is a critical tool for determining the potential consequences of an impact…. It is widely used by government and scientific agencies as well as impact research groups and space enthusiasts around the world.”

The simulator is actually an update to the basic tool already used by astronomers and governments to study how an impact would change Earth, to plan for post-disaster scenarios, and to explore asteroid- and comet-deflection technologies. When our planet was young many more space objects crashed into the Earth; while the barrage has slowed, small bits of debris still frequently fly into our atmosphere, says Time:

It’s still a dangerous cosmos out there, and the Earth gets beaned all the time — with about 100 tons of detritus from comets and asteroids hitting us each day. The overwhelming share of the material — including chunks of rock as big as a car — will incinerate in the atmosphere well before hitting the ground, but about once every 100 years or so, something significant gets through.

At the website you need to define your space object (the diameter, the density), the impact (angle and velocity), the target (what it will hit), and the distance from which you will be observing the impact. Each of these factors affects what will happen to the Earth (and to you) after the impact occurs.

Your apres-impact scores include the size of the crater, changes to the Earth’s rotation, and seismic and radiation effects at your chosen observation point. But the impact crater isn’t the only problem that would result from a moderate sized impact, Jay Melosh, who helped develop the software, told USA Today:

“The chance of a 1 km diameter object hitting the Earth in the next 1000 years is 1 in 1000, so on the face of it, this is not much to worry about. On the other hand, an object of this size, while not a 15 km dinosaur-killer, would have side effects on climate that could lead to global crop failures lasting a few years, so perhaps 90% of humanity would die.”